Vascular stent with improved vessel wall apposition

ABSTRACT

A medical device is provided that includes a vessel-engaging member attached to a distal end of a delivery wire. The vessel-engaging member includes a plurality of rows, with each row having a plurality of struts arranged in an alternating pattern such that for each row, a first set of vertices is positioned on a proximal side, and a second set of vertices is positioned on a distal side. The vessel-engaging member further includes a plurality of single bridges positioned between adjacent rows, each of the bridges connecting a vertex of a first row with a corresponding vertex of an adjacent second row. The vessel-engaging member can also include a plurality of double bridges positioned between adjacent rows, each of the double bridges connecting a vertex of a first row with two adjacent vertices of an adjacent second row.

BACKGROUND

Neurovascular (e.g., cerebral) aneurysms affect about 5% of thepopulation. Aneurysms may be located, for example, along arterial sidewalls. The aneurysms may have a fundus, a neck, and a fundus-to-neckratio or “neck ratio.” If the neck ratio is greater than 2 to 1 or ifthe neck is less than 4 mm, the aneurysm may be treated withembolization coils alone because the coils will generally constrainthemselves within the aneurysm without herniating into parent vessels.If the neck ratio is less than 2 to 1 or if the neck is greater than 4mm, the aneurysms may be difficult to treat with embolization coilsalone because the coils may be prone to herniating, or dislodging, intoparent vessels. Dislodging of coils may cause arterial occlusion,stroke, and/or death.

In order to inhibit such dislodging, tubular neck remodeling devices maybe used to keep coils or other materials within the fundus of theaneurysm and out of the vessels. Tubular remodeling devices generallyconsist of a braided wire or cut metallic stent or stents covering theneck of the aneurysm so that materials introduced into the fundus of theaneurysm do not herniate out of the aneurysm.

SUMMARY

The subject technology is illustrated, for example, according to variousaspects described below. Various examples of aspects of the subjecttechnology are described as numbered clauses (1, 2, 3, etc.) forconvenience. These are provided as examples, and do not limit thesubject technology. It is noted that any of the dependent clauses may becombined in any combination, and placed into a respective independentclause, e.g., clause 1, 20, 32, and 50. The other clauses can bepresented in a similar manner.

1. A medical device, comprising:

-   -   a delivery wire having a proximal end and a distal end; and    -   a vessel-engaging member attached to the distal end of the        delivery wire, the vessel-engaging member comprising:    -   a plurality of rows, each row having a plurality of struts        arranged in an alternating pattern such that for each row, a        first set of vertices is positioned on a proximal side, and a        second set of vertices is positioned on a distal side;    -   a plurality of single bridges positioned between adjacent rows,        each of the bridges connecting a vertex of a first row with a        corresponding vertex of an adjacent second row; and    -   a plurality of double bridges positioned between adjacent rows,        each of the double bridges connecting a vertex of a first row        with two adjacent vertices of an adjacent second row, wherein        each of the plurality of double bridges is arranged generally        along a line progressing laterally at an angle with respect to a        longitudinal axis of the member.

2. The medical device of clause 1, wherein the first set of vertices arelaterally offset from the second set of vertices.

3. The medical device of clause 1, wherein the plurality of singlebridges positioned between a first row and an adjacent second row extendfrom the second set of vertices of the first row, downward to the firstset of vertices of the second row, and wherein the plurality of singlebridges positioned between the second row and an adjacent third rowextends from the second set of vertices of the second row, upward to thefirst set of vertices of the third row.

4. The medical device of clause 1, wherein the plurality of doublebridges are more rigid than the plurality of single bridges and therebycommunicate a larger proportion of a longitudinal force than theplurality of single bridges.

5. The medical device of clause 1, wherein the plurality of singlebridges comprises undulating members.

6. The medical device of clause 1, wherein the plurality of doublebridges comprises undulating members.

7. The medical device of clause 1, wherein the single bridges positionedbetween a first row and an adjacent second row alternate laterally withthe double bridges positioned between said adjacent rows.

8. The medical device of clause 7, wherein the alternating single anddouble bridges form a laterally-repeating pattern of two adjacent singlebridges and one double bridge adjacent to one of the two adjacent singlebridges.

9. The medical device of clause 8, wherein the single and double bridgespositioned between the second row and an adjacent third row form thesame laterally-repeating pattern as between the first row and the secondrow, wherein the double bridges between the second and third row areoffset laterally from the double bridges between the first and secondrow.

10. The medical device of clause 8, wherein:

-   -   the single and double bridges positioned between the second row        and an adjacent third row form the same laterally-repeating        pattern as between the first row and the second row;    -   the single and double bridges positioned between the third row        and an adjacent fourth row form the same laterally-repeating        pattern as between the first row and the second row, and as        between the second row and the third row;    -   the double bridges between the second row and the third row are        aligned laterally with the double bridges between the first row        and the second row; and    -   the double bridges between the third row and the fourth row are        offset laterally from the double bridges between the first row        and the second row, and from the double bridges between the        second row and the third row.

11. The medical device of clause 10, wherein the pattern thus formed bythe double bridges between the first row and the second row, the doublebridges between the second row and the third row, and the double bridgesbetween the third row and the fourth row, consisting of twolongitudinally adjacent, laterally aligned sets of double bridgesfollowed by one set of double bridges longitudinally adjacent to one ofthe two aligned sets and laterally offset therefrom, repeats along thelength of the medical device.

12. The medical device of clause 10, wherein the double bridges betweenthe third row and the fourth row are offset laterally from the doublebridges between the first row and the second row, and from the doublebridges between the second row and the third row, to the next lateralinter-vertex position on the distal vertices of the third row.

13. The medical device of clause 1, wherein the plurality of singlebridges and the plurality of double bridges positioned between a firstrow and an adjacent second row are laterally offset from the pluralityof single bridges and the plurality of double bridges positioned betweenthe second row and an adjacent third row.

14. The medical device of clause 1, wherein an adjacent plurality ofdouble bridges is positioned between the second row and a third row, theadjacent plurality of double bridges being longitudinally spaced fromthe plurality of double bridges.

15. The medical device of clause 1, further comprising first and secondtapered sections, each of the tapered sections projecting from aproximal row and tapering in a direction from the proximal row towardthe delivery wire.

16. The medical device of clause 15, wherein the first tapered sectioncomprises a first and second connecting member with distal endsconnected to the proximal row and proximal ends connected to the firsttapered section.

17. The medical device of clause 16, wherein the first and secondconnecting members intersect.

18. The medical device of clause 15, wherein the first tapered sectionis connected to the proximal row at a middle vertex and a first strutendpoint, and the second tapered section is connected to the proximalrow at the middle vertex and a second strut endpoint.

19. A medical device for insertion into a vessel, comprising:

-   -   a frame comprising a plurality of rows, each row having a        plurality of struts arranged in an alternating pattern such that        for each row, a first set of vertices is positioned on a        proximal side, and a second set of vertices is positioned on a        distal side offset from the first set of vertices;    -   a plurality of single bridges positioned between adjacent rows,        each of the bridges connecting the second set of vertices of a        first row with the first set of vertices of a second row; and    -   a plurality of double bridges positioned between adjacent rows,        each of the double bridges connecting a vertex of the first row        with two vertices of the second row, wherein each of the        plurality of double bridges is arranged generally along a line        progressing laterally at an angle with respect to a longitudinal        axis of the member.

20. The medical device of clause 19, wherein the first set of verticesare laterally offset from the second set of vertices.

21. The medical device of clause 19, wherein the plurality of singlebridges positioned between a first row and an adjacent second row extendfrom the second set of vertices of the first row, downward to the firstset of vertices of the second row, and wherein the plurality of singlebridges positioned between the second row and an adjacent third rowextends from the second set of vertices of the second row, upward to thefirst set of vertices of the third row.

22. The medical device of clause 19, wherein the plurality of doublebridges are more rigid than the plurality of single bridges and therebycommunicate a larger proportion of a longitudinal force than theplurality of single bridges.

23. The medical device of clause 19, wherein the plurality of singlebridges comprises undulating members.

24. The medical device of clause 19, wherein the plurality of doublebridges comprises undulating members.

25. The medical device of clause 19, wherein the single bridgespositioned between a first row and an adjacent second row alternatelaterally with the double bridges positioned between said adjacent rows.

26. The medical device of clause 25, wherein the alternating single anddouble bridges form a laterally-repeating pattern of two adjacent singlebridges and one double bridge adjacent to one of the two adjacent singlebridges.

27. The medical device of clause 26, wherein the single and doublebridges positioned between the second row and an adjacent third row formthe same laterally-repeating pattern as between the first row and thesecond row, wherein the double bridges between the second and third roware offset laterally from the double bridges between the first andsecond row.

28. The medical device of clause 26, wherein:

-   -   the single and double bridges positioned between the second row        and an adjacent third row form the same laterally-repeating        pattern as between the first row and the second row;    -   the single and double bridges positioned between the third row        and an adjacent fourth row form the same laterally-repeating        pattern as between the first row and the second row, and as        between the second row and the third row;    -   the double bridges between the second row and the third row are        aligned laterally with the double bridges between the first row        and the second row; and    -   the double bridges between the third row and the fourth row are        offset laterally from the double bridges between the first row        and the second row, and from the double bridges between the        second row and the third row.

29. The medical device of clause 28, wherein the pattern thus formed bythe double bridges between the first row and the second row, the doublebridges between the second row and the third row, and the double bridgesbetween the third row and the fourth row, consisting of twolongitudinally adjacent, laterally aligned sets of double bridgesfollowed by one set of double bridges longitudinally adjacent to one ofthe two aligned sets and laterally offset therefrom, repeats along thelength of the medical device.

30. The medical device of clause 28, wherein the double bridges betweenthe third row and the fourth row are offset laterally from the doublebridges between the first row and the second row, and from the doublebridges between the second row and the third row, to the next lateralinter-vertex position on the distal vertices of the third row.

31. The medical device of clause 19, wherein the plurality of singlebridges and the plurality of double bridges positioned between a firstrow and an adjacent second row are laterally offset from the pluralityof single bridges and the plurality of double bridges positioned betweenthe second row and an adjacent third row.

32. The medical device of clause 19, wherein an adjacent plurality ofdouble bridges is positioned between the second row and a third row, theadjacent plurality of double bridges being longitudinally spaced fromthe plurality of double bridges.

33. The medical device of clause 19, further comprising first and secondtapered sections, each of the tapered sections projecting from aproximal row and tapering in a direction from the proximal row towardthe delivery wire.

34. The medical device of clause 33, wherein the first tapered sectioncomprises a first and second connecting member with distal endsconnected to the proximal row and proximal ends connected to the firsttapered section.

35. The medical device of clause 34, wherein the first and secondconnecting members intersect.

36. The medical device of clause 33, wherein the first tapered sectionis connected to the proximal row at a middle vertex and a first strutendpoint, and the second tapered section is connected to the proximalrow at the middle vertex and a second strut endpoint.

37. A method of implanting a medical device in a patient'sneurovasculature comprising:

-   -   inserting a guide catheter into the neurovasculature;    -   advancing a microcatheter through a distal end of the guide        catheter;    -   advancing a vessel-engaging member through the microcatheter        such that a distal portion of the member is located adjacent a        treatment site in the neurovasculature, wherein the member        comprises:        -   a plurality of rows, each row having a plurality of struts            arranged in an alternating pattern such that for each row, a            first set of vertices is positioned on a proximal side and a            second set of vertices is positioned on a distal side;        -   a plurality of single bridges positioned between adjacent            rows, each of the bridges connecting a vertex of a first row            with a corresponding vertex of a second row; and        -   a plurality of double bridges positioned between adjacent            rows, each of the double bridges connecting a vertex of a            first row with two adjacent vertices of an adjacent second            row, wherein each of the plurality of double bridges is            arranged generally along a line progressing laterally at an            angle with respect to a longitudinal axis of the member; and    -   withdrawing the microcatheter relative to the member to expose        the member, the member being configured to expand against and        engage the treatment site when unrestrained by the        microcatheter.

38. The method of clause 37, wherein expanding against and engaging thetreatment site comprises extending the vessel-engaging member across aneck of an aneurysm, wherein the vessel-engaging member inhibitsdislodging of objects out of the neck of the aneurysm.

39. The method of clause 38, further comprising inserting embolicmaterial into a fundus of the aneurysm.

40. The method of clause 38, wherein inserting embolic materialcomprises inserting coils.

41. The method of clause 37, further comprising detaching thevessel-engaging member via a connection mechanism.

42. The method of clause 41, wherein the connection mechanism comprisesan electrolytically severable region.

43. The method of clause 41, wherein the electrolytically severableregion comprises a member extending between first and second taperedsections, each of the tapered sections projecting from a proximal row ofthe vessel-engaging member and tapering in a direction from the proximalrow toward a delivery wire attached to the vessel-engaging member.

44. The method of clause 41, wherein the connection mechanism comprisesinterlocking fingers disposed on a proximal end of the vessel-engagingmember, the fingers configured to couple a delivery wire.

45. The method of clause 41, wherein the connection mechanism comprisesa ball disposed at a distal end of a delivery wire and two paddlesdisposed on a proximal end of the vessel-engaging member, the paddlesconfigured to couple the ball using a retractable sleeve that surroundsthe paddles and the ball.

46. The method of clause 41, further comprising advancing longitudinallyor distally the vessel-engaging member prior to detachment.

47. The method of clause 46, wherein the advancing comprisestransmitting a majority of a longitudinal force from a pusher wire to adistal end of the member using the plurality of double bridges.

48. The method of clause 47, wherein the pusher wire is coupled to aproximal end of the vessel-engaging member.

49. The method of clause 46, wherein the advancing comprisestransmitting a majority of a twisting force from a pusher wire to adistal end of the member using the plurality of double bridges.

50. The method of clause 37, wherein the treatment site is at a tortuouscurve in an anatomical lumen.

51. A method of implanting a medical device in an anatomical lumen, themethod comprising:

-   -   inserting a vessel-engaging member into the lumen, the member        comprising:        -   a plurality of rows, each row having a plurality of struts            arranged in an alternating pattern such that for each row, a            first set of vertices is positioned on a proximal side and a            second set of vertices is positioned on a distal side;        -   a plurality of single bridges positioned between adjacent            rows, each of the bridges connecting a vertex of a first row            with a corresponding vertex of a second row; and        -   a plurality of double bridges positioned between adjacent            rows, each of the double bridges connecting a vertex of a            first row with two corresponding vertices of a second row,            wherein each of the plurality of double bridges is arranged            generally along a line progressing laterally at an angle            with respect to a longitudinal axis of the member; and    -   advancing the vessel-engaging member along the lumen by        transmitting a majority of a longitudinal pushing force from a        pusher, along the plurality of double bridges, to a distal        portion of the member.

52. The method of clause 51, wherein the pusher is coupled to a proximalend of the vessel-engaging member.

53. The method of clause 51, wherein the advancing comprisestransmitting a majority of a twisting force from a pusher, along theplurality of double bridges, to a distal portion of the member.

54. The method of clause 51, wherein the advancing comprises advancingthe vessel-engaging member within a catheter in the lumen.

55. The method of clause 54, wherein the vessel-engaging member isadvanced within the catheter while the vessel-engaging member isexpanded against an inner wall of the catheter.

56. The method of clause 51, wherein the anatomical lumen comprises atortuous curve.

It is understood that other configurations of the subject technologywill become readily apparent to those skilled in the art from thefollowing detailed description, wherein various configurations of thesubject technology are shown and described by way of illustration. Aswill be realized, the subject technology is capable of other anddifferent configurations and its several details are capable ofmodification in various other respects, all without departing from thescope of the subject technology. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description will be made with reference to the accompanyingdrawings:

FIG. 1A depicts a medical device according to some embodiments of thesubject technology.

FIG. 1B depicts a perspective view of a strut according to someembodiments of the subject technology.

FIG. 1C depicts a cross-sectional view of a strut according to someembodiments of the subject technology.

FIG. 2 depicts a flat pattern of a medical device according to someembodiments of the subject technology.

FIG. 3 depicts a flat pattern of a medical device according to someembodiments of the subject technology.

FIG. 4 depicts an electrolytically severable connection mechanismaccording to some embodiments of the subject technology.

FIG. 5 depicts a top view of an electrolytically severable connectionmechanism according to some embodiments of the subject technology.

FIG. 6 depicts a perspective view of an electrolytically severableconnection mechanism according to some embodiments of the subjecttechnology.

FIG. 7 depicts a perspective view of a mechanically severable connectionmechanism according to some embodiments of the subject technology.

FIG. 8 depicts a mechanically severable connection mechanism accordingto some embodiments of the subject technology.

FIG. 9 depicts a partial cross section of a compressed medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 10 depicts a partial cross section of an expanded medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 11 depicts a partial cross section of a compressed medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 12 depicts a partial cross section of an expanded medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 13 depicts a perspective view a mechanically severable connectionmechanism according to some embodiments of the subject technology.

FIG. 14 depicts a partial cross section of a compressed medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 15 depicts a partial cross section of an expanded medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 16 depicts a partial cross section of a compressed medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 17 depicts a partial cross section of an expanded medical devicehaving a mechanically severable connection mechanism according to someembodiments of the subject technology.

FIG. 18 illustrates a side view of a medical device in a tortuous lumenaccording to some embodiments of the subject technology.

DETAILED DESCRIPTION

The detailed description set forth below is intended as a description ofvarious configurations of the subject technology and is not intended torepresent the only configurations in which the subject technology may bepracticed. The appended drawings are incorporated herein and constitutea part of the detailed description. The detailed description includesspecific details for the purpose of providing a thorough understandingof the subject technology. However, it will be apparent to those skilledin the art that the subject technology may be practiced without thesespecific details. In some instances, well-known structures andcomponents are shown in block diagram form in order to avoid obscuringthe concepts of the subject technology.

There have been numerous problems in the use of stents and vasooclusivedevices within the vasculature of the human body. Some devices ovalizewhen placed in a tortuous anatomical lumen. This may also be referred toas “kinking” or “fish mouthing.” Other devices may herniate into ananeurysm. This problem may be referred to as “gator-backing”, “Ishelling”, and “ledge effect”. Some devices abruptly move distally, or“jump,” during the last portion of stent deployment. This may cause theproximal portion of the stent to protrude into the aneurysm also knownas “ice cream cone” if the length is not oversized. Consequently, stentsare often seen as having thrombogenic properties. Due to the need to useanticoagulants with such stents, few doctors have been known to becomfortable using such stents to treat a ruptured aneurysm. In someinstances, an aneurysm may be ballooned and coiled, and then a stent isplaced several weeks later to minimize the thrombogenic effect.Furthermore, visibility of stents under fluoroscopy is often difficult,and the trackability of stents in the vasculature has not been optimal.

The medical devices of the subject technology solves some or all of theforegoing problems by providing a vessel-engaging member designed forbridging a neck of an aneurysm that effectively prevents herniation orprolapse of objects (e.g., embolization coils, thrombi, etc.) out of theneck of the aneurysm. The vessel-engaging member may also allow theinsertion of embolic material therethrough. The embolization coils maybe a single embolization coil or other embolic material (e.g., embolicfluid).

The embolization coils or other embolic material may be inserted into afundus of the aneurysm before or after positioning and deployment of thevessel-engaging member in an anatomical lumen or vessel. In someembodiments, the embolization coils are inserted in the fundus of theaneurysm using the same catheter from which the vessel-engaging memberis deployed. In other embodiments, the embolization coils are insertedin the fundus of the aneurysm using a different catheter than thecatheter from which the vessel-engaging member is deployed. In certainsuch embodiments, a guidewire may be used to guide both catheters.

The vessel-engaging member may engage a wall of the lumen utilizingvarious suitable means. For example, the vessel-engaging member may be aself-expanding stent and/or a balloon-expandable stent. In someembodiments, “vessel” or “lumen” may refer to blood vessels (includingarteries and veins) or other suitable body organs having a lumen, suchas the gastrointestinal tract (e.g., esophagus, stomach, smallintestine, colon, rectum), bile ducts, urinary bladder, ureter, urethra,trachea, bronchi, and the like. As will be seen below, the medicaldevice is designed such that a fully-deployed circumference of thevessel-engaging member more uniformly tracks an anatomical lumen, evenin tortuous curvatures. The double bridge-strut configuration of thesubject technology improves wall apposition, coil support, trackability,deployment accuracy, and radiopacity.

FIG. 1A depicts a medical device including struts, single bridges, anddouble bridges, according to some embodiments of the subject technology.The medical device includes a delivery wire 153 (as shown in FIG. 4)having a proximal end and a distal end, and a frame or vessel-engagingmember 100 attached to the distal end of the delivery wire 153.Referring to FIG. 1, the vessel-engaging member 100 includes a proximalend 101 and a distal end 102, and may be comprised of struts 103, singlebridges 104A, and double bridges 104B. For example, the vessel-engagingmember 100 may include a plurality of rows 106, with each row 106 havinga plurality of struts 103 arranged in an alternating pattern such thatfor each row 106, a first set of vertices 107A is positioned on aproximal side, and a second set of vertices 107B is positioned on adistal side. The vessel-engaging member 100 may further include aplurality of single bridges 104A positioned between adjacent rows, witheach of the single bridges 104A connecting a vertex 107 of a first rowwith a corresponding vertex 107 of an adjacent second row. Thevessel-engaging member 100 may also include a plurality of doublebridges 104B positioned between adjacent rows, with each of the doublebridges 104B connecting a vertex 107 of a first row with two adjacentvertices 107 of an adjacent second row. The device may further includetwo tapered protrusions 105 at the proximal end 101 of the device forconnecting the vessel-engaging member 100 to the delivery wire 153 (asshown in FIG. 4). In FIG. 1A, the vessel-engaging member 100 is showncut longitudinally and laid flat.

The rows 106 of struts may be joined together at their vertices 107 bythe plurality of single bridges 104A and the plurality of double bridges104B. While nine rows 106 of struts 103 are illustrated in FIG. 1A, itis understood that any number greater than two rows of struts aresuitable for the disclosure. As shown by FIG. 1A, the struts 103 of eachrow 106 may be alternatively positioned at a substantially 75 degreeangle relative to each other in a zigzag-like pattern. Each vertex 107(or bend point) is connected by a single bridge 104A or a double bridge104B to a corresponding vertex or vertices of an adjacent row of struts.

As depicted by FIG. 1A, each row 106 may include twelve struts 103, eachstrut 103 alternating direction in a zigzag pattern. The strut lengthmay, for example, range from about 1.50 millimeters (mm) to about 2.25mm. Other strut lengths may be selected without departing from the scopeof the technology. For example, the strut lengths may also be selectedto be shorter to create more points to bend as the strut is flexedlongitudinally and/or compressed or flexed at its diameter.

FIG. 1B depicts a perspective view of a strut 103 according to someembodiments of the subject technology. FIG. 1C depicts a cross-sectionalview of the strut 103 according to one aspect of the subject technology.As shown, the strut 103 has a rectangular cross-section. In someembodiments, a single bridge 104A or double bridge 104B may have asimilar rectangular cross-section. However, the strut 103, the singlebridge 104A, and the double bridge 104B, may have other suitablecross-sectional shapes, such as an elliptical cross-section (e.g.,circular) or a polygonal cross-section.

In some embodiments, a strut width at the tip or vertex 107 of the strut103 may be sized slightly larger than its width. For example, wherein astrut width of 0.055 is selected, a tip or vertex width of approximately0.065 mm may be selected. The increased strength resulting from theincreased width of the tips or vertices 107 may enhance durability ofthe medical device, for example, during deployment or retraction of themedical device from a deploying micro-catheter. In further aspects, oneor more strut tip widths may be reduced to distribute strain on themedical device when deployed in certain tortuous configurations.

Referring to FIG. 1A, the plurality of single bridges 104A and theplurality of double bridges 104B may comprise undulating or straightmembers which extend in a generally lateral or radial direction. As usedherein, a lateral direction is defined as a direction that isperpendicular to a longitudinal axis 109, and may be used to describefeatures of a flat pattern of the vessel-engaging member 100 as shown inFIG. 1A. In addition, as used herein, a radial direction is defined as adirection that is normal to the longitudinal axis 109 of thevessel-engaging member 100 that is along a radius of the vessel-engagingmember 100. As described further below, a first edge 119 and a secondedge 120 of the vessel-engaging member 100 may be connected to eachother to form a substantially cylindrical shape by welding, soldering,or otherwise joining the strut tips 111 of the first edge 119 with thestrut tips 111 of the second edge. Accordingly, a feature that isdescribed as having a lateral characteristic in a flat pattern of thevessel-engaging member 100, may have a radial characteristic in acylindrical shaped vessel-engaging member 100.

The single and double bridges, 104A and 104B respectively, may have alength ranging from about 1.5 mm to about 1.8 mm. As with strut lengths,the bridge length may be varied to be shorter or longer than thedisclosed range without departing from the scope of the invention.

As depicted by FIG. 1A, the plurality of single bridges 104A and theplurality of double bridges 104B may be configured to maintain the firstset of vertices 107A, of a row 106, substantially inline. In addition,the plurality of single bridges 104A and the plurality of double bridges104B may be configured to maintain the second set of vertices 107B, of arow 106, substantially inline For a given row 106, the first set ofvertices 107A may be laterally or radially offset from the second set ofvertices 107B. For example, the distal vertices 107B may laysubstantially along a line 128 that is parallel to the longitudinal axis109 and the proximal vertices 107A may lay outside the line 128.

In some embodiments, each row 106 is mirrored and laterally shiftedrelative to an adjacent row, such that the vertices 107 connected by theplurality of single bridges 104A or the plurality of double bridges 104Bare facing each other, inward, toward the bridges. Thus, while eachbridge connects a mirrored vertex 107, the vertices of the rows 106 mayappear to be oriented in the same direction. The configuration andarrangement of struts 103 and the plurality of single bridges 104Acreates a matrix of cells 110 over the surface of the vessel-engagingmember 100.

Referring to FIG. 1A, the single bridges 104A positioned between a firstrow 106A and an adjacent second row 106B may alternate laterally orradially with the double bridges 104B positioned between said first row106A and second row 106B. For example, for a given row 106, thealternating single and double bridges, 104A and 104B respectively, mayform a laterally-repeating pattern of two adjacent single bridges 104Aand one double bridge 104B adjacent to one of the two adjacent singlebridges 104A.

In some embodiments, the laterally-repeating pattern of the plurality ofsingle bridges 104A and the plurality of double bridges 104B may repeatalong two or more rows 106. For example, the single and double bridgespositioned between the second row 106B and an adjacent third row 106C,may form the same laterally-repeating pattern as between the first row106A and the second row 106B, described above. In addition, the singleand double bridges positioned between the third row 106C and an adjacentfourth row 106D, may also form the same laterally-repeating pattern asbetween the first row 106A and the second row 106B, and as between thesecond row 106B and the third row 106C. In some embodiments, the doublebridges positioned between the second row 106B and the third row 106Cmay be aligned laterally with the double bridges positioned between thefirst row 106A and the second row 106B. In other words, the plurality ofdouble bridges 104B positioned between the second row 106B and the thirdrow 106C may be longitudinally spaced from the plurality of doublebridges 104B positioned between the first row 106A and the second row106B.

In some embodiments, the double bridges positioned between the third row106C and the fourth row 106D may be offset laterally or radially fromthe double bridges positioned between the first row 106A and the secondrow 106B, and from the double bridges positioned between the second row106B and the third row 106C. The double bridges 104B positioned betweenthe third row 106C and the fourth row 106D may be offset laterally orradially from the double bridges 104B positioned between the first row106A and the second row 106B, and from the double bridges 104Bpositioned between the second row 106B and the third row 106C, to thenext lateral inter-vertex position on the distal vertices 107B of thethird row 106C.

As shown in FIG. 1A, the pattern thus formed by the double bridges 104Bpositioned between the first row 106A and the second row 106B, thedouble bridges 104B positioned between the second row 106B and the thirdrow 106C, and the double bridges 104B positioned between the third row106C and the fourth row 104D, may comprise two longitudinally adjacent,laterally aligned sets of double bridges 108A followed by one set ofdouble bridges 108B longitudinally adjacent to one of the two alignedsets 108A and laterally offset therefrom.

In some embodiments, the pattern formed by the sets of double bridges108A, 108B, may repeat along the length of the medical device. Each ofthe plurality of double bridges 104B may therefore, be arrangedgenerally along one or more lines progressing laterally at an angle withrespect to the longitudinal axis 109 of the vessel-engaging member 100.Although the sets of double bridges 108A, 108B depicted in FIG. 1A eachinclude two double bridges 104B, it is understood that the sets ofdouble bridges 108A, 108B may each include more than two double bridges104B. Alternatively, it is also understood that the sets of doublebridges 108A, 108B may each include only a single double bridge 104B.

Referring to FIG. 1A, the plurality of single bridges 104A positionedbetween the first row 106A and the adjacent second row 106B, may extendfrom the second set of vertices 107B of the first row 106A, downward tothe first set of vertices 107A of the second row 106B. Downward, as usedherein, refers to laterally or radially in one direction, while upwardrefers to laterally or radially in the opposite direction. The pluralityof single bridges 104A positioned between the second row 106B and theadjacent third row 106C may extend from the second set of vertices 107Bof the second row 106B, upward to the first set of vertices 107A of thethird row 106C.

In some embodiments, the plurality of double bridges 104B are more rigidthan the plurality of single bridges 104A. For example, because thedouble bridge 104B comprises two undulating members that connect adistal vertex 107B to two corresponding proximal vertices 107A, thedouble bridge 104B increases the rigidity of the vessel-engaging member100. In contrast, the single bridge 104A comprises one undulating memberthat connects a distal vertex 107B to only one corresponding proximalvertex 107A. Accordingly, the double bridge 104B is more rigid than thesingle bridge 104A.

The plurality of double bridges 104B may communicate a majority orlarger proportion of a longitudinal or twisting force than the pluralityof single bridges 104A because the double bridges 104B are more rigidthan the single bridges 104A. Generally, a load or force may betransmitted through the vessel-engaging member via the struts 103, thesingle bridges 104A, and the double bridges 104B. Because the doublebridges 104B comprise two undulating members, compared to the singleundulating member of the single bridge 104A, the double bridge 104B maycommunicate a larger proportion of the longitudinal or twisting forcethan adjacent single bridges 104A. Accordingly, the double bridges 104Btransmit a majority of the longitudinal or twisting force from a pusheror delivery wire to the distal end 102 of the vessel-engaging member100. Although the single and double bridges 104A, 104B are depicted asundulating members in FIG. 1A, it is understood that the single and/ordouble bridges 104A, 104B may comprise straight members. For thepurposes of this disclosure, the subject technology may use a deliverywire and/or a pusher wire without limitation. In this regard, the termdelivery wire may refer to what one skilled in the art may call a pusherwire and vice versa. Therefore, for simplicity, the terms delivery wireand pusher wire are used interchangeably.

In some embodiments, the single or double bridges, 104A and 104Brespectively, may be thinner in width relative to the struts 103. Forexample, a strut width may range from about 0.055 mm to about 0.065 mmto provide sufficient radial support when the vessel-engaging member 100is deployed in the anatomical lumen. In contrast, a width of the singleor double bridges, 104A and 104B respectively, may range from about0.045 mm to about 0.055 mm. Accordingly, the subject technology mayinclude a thinner bridge width to enhance longitudinal flexibility, andprovide better arching capability. When deployed in a tortuousanatomical lumen, the vessel-engaging member 100 will be more likely tobend at a single or double bridge, 104A and 104B respectively, locationthan at a strut 103 location, thus providing improved wall apposition ata curve.

The medical device may be implanted in a patient's neurovasculature byfirst inserting a guide catheter into the neurovasculature, thenadvancing a microcatheter through a distal end of the guide catheter,and then advancing the vessel-engaging member 100 through themicrocatheter such that the distal portion 102 of the vessel-engagingmember 100 is located adjacent a treatment site in the neurovasculature.After withdrawing the microcatheter relative to the vessel-engagingmember 100 to expose and allow the vessel-engaging member 100 to expandagainst and engage the treatment site, the single bridges 104A and/orthe double bridges 104B may bend and/or deflect to thereby allow thestruts 103 to conform to the tortuous curvature of the lumen.

For example, referring to FIG. 18, the lumen 200 may have a diameter ofabout 3 mm and may include a curve with a center point 220, having aradius 210 of about 3.9 mm. The curve may have an apex 230 located at amidpoint of the curve. The apex may also represent a peak of the curve,or a point on the curve equidistant from endpoints of the curve. At theapex 230, the single or double bridges, 104A and 104B respectively,adjacent the apex 230 are deflected to allow the vertices 107 adjacentto the deflecting bridges to contact an inner surface of the vessel orlumen, thereby providing improved wall apposition near the apex 230. Insome embodiments, a distance between strut rows 106 disposed adjacent tothe deflecting bridges is less than a distance between strut rowsdisposed away from the deflecting bridges. The reduced distance betweenthe strut rows may cause the vertices 107 adjacent to the apex 230 to benear each other. In some embodiments, by allowing the vertices 107 tomove near each other, the vertices 107 may better conform to the shapeof the curve.

Because the vessel-engaging member 100 may better conform to the shapeof the curve, the vessel-engaging member 100 is capable of effectivelyextending across a neck of an aneurysm 202 to inhibit dislodging ofobjects 203 out of the neck of the aneurysm 202.

Tapered Sections

As depicted by FIG. 1A, the device may also include one or more taperedsections 105 projecting from a proximal row 106P of struts and taperingin a direction from the proximal row 106P toward the delivery wire 153(shown in FIG. 4). In some embodiments, the struts of the proximal(and/or distal) row may be selected to be longer than the struts ofother rows 106. The proximal row 106P may be used for connecting theprimary, workable structure of the medical device to the one or moretapered sections 105. For example, referring to FIG. 1A, each taperedsection 105 may extend from four vertices 107 of the proximal row 106P,with each tapered section sharing an intermediate-positioned vertex.Each tapered section 105 may include a V shaped structure extending fromthe outer most end points (strut tips 111), and an X shaped structurewithin and supporting the V shaped structure, extending from the innermost vertices of proximal row 106P. For example, a first and secondconnecting member, 121 and 122 respectively, may extend from the innermost vertices of the proximal row 106P to the tapered section 105. Thefirst and second connecting members, 121 and 122 respectively, mayintersect thereby forming the X. The proximal end point of each taperedsection (vertex of the V shaped structure) may further include aconnection point 113 for detachable connection to a delivery wire, asdiscussed further below. Each delivery wire connection point 113 (and/orvertex of the V shaped structure) may be constructed from a radiopaquematerial or include a radiopaque marker allowing in vivo imaging of thestent.

Each tapered section 105 may have a length measured along thelongitudinal axis. As shown in FIG. 1A, the tapered sections 105 mayhave a similar or identical length. As shown in FIGS. 2 and 3, thetapered sections 105 may have dissimilar lengths. For example, referringto FIG. 2, the length of one of the tapered sections may be less thanthe length of another tapered section. Specifically, the vessel-engagingmember 100 may have a working, or active, region 123 configured toperform a medical procedure and a first and second non-working, orinactive, region, 124 and 125 respectively. Each region may have alength. The working region 123 may comprise the plurality of rows 106and a portion 126 of the tapered sections 105. The first non-workingregion 124 may comprise a remaining portion of a first tapered section114. The second non-working region 125 may comprise a remaining portionof a second tapered section 115. In some embodiments, to minimizethrombogenic effects, the length of the tapered sections 105 should beminimized. Accordingly, the first non-working region 124 may have alength ranging from about 3.3 mm to about 2.6 mm and the secondnon-working region 125 may have a length ranging from about 5.3 mm toabout 4.6 mm. In some embodiments, the difference in length between thetapered sections 114, 115 allows the connection points 113 to be alignedwith one another when the vessel-engaging member 100 is collapsed (e.g.,when the vessel-engaging member 100 is stowed as opposed to beingdeployed).

Referring to FIG. 1A, the one or more taper sections 105 may haveindividual cells 127 that have a different size than the individualcells 110. For example, in some embodiments, the taper sections 105 mayhave individual cells 127 that have a size larger than that of theindividual cells 110. Each taper section 105 may taper gradually towardsa connection mechanism 113, or some other connection point along themedical device that connects the vessel-engaging member 100 to thedelivery wire.

In some embodiments, the tapered sections 105 allows the delivery wireto act directly on the device via the shorter tapered section 114, withthe longer tapered section 115 providing stability and control. In thisregard, the tapered sections 105 and complete circular design of thevessel-engaging member 100 in its deployed state may improvetrackability, and may act to minimize retrieval forces, minimize thenon-working length, improve pushability, and the like. For example, thevessel-engaging member 100 may have a delivery or pushability force ofless than 20 N (Newton). In other examples, the delivery or pushabilityforce may be less than 15 N, 10 N, 5 N, or 1 N. The vessel-engagingmember 100 may also have a retrieval force of less than 10 N. In otherexamples, the retrieval force may be less than 5 N, 2 N, or 1 N. Whenfully expanded, the improved wall apposition enabled by the subjecttechnology may also work to minimize thrombogenic effects. In someembodiments, a non-thrombogenic coating may further be applied to thedevice to further reduce the thrombogenicity of the device.

In one aspect, the one or more tapered sections 105 facilitateresheathing of the proximal portion of the vessel-engaging member 100into the microcatheter. For example, an inner surface of themicrocatheter may act upon the one or more tapered sections 105 tothereby collapse the vessel-engaging member 100 and cause it to fitwithin the microcatheter. The taper of the one or more tapered sections105 thereby provide a ramping surface to cause the vessel-engagingmember 100 to collapse. The device may therefore be resheathed in orderto reposition or slightly adjust the position of the device within thelumen. In another aspect, the one or more tapered sections 105 mayfacilitate retrieval of a thrombus during a blood flow restorationprocedure. For example, after the thrombus is entrained within thevessel-engaging member 100, the thrombus may be retrieved by resheathingthe vessel-engaging member 100 using the one of more tapered sections105 and the microcatheter.

In some embodiments, a width of the single and double bridges 104A, 104Bdisposed between the proximal row 106P and an adjacent row may be widerthan other bridges of the vessel-engaging member 100. For example,referring to FIG. 2, the width of the proximal single and double bridges112 may be 0.055 mm, whereas the width of the remaining single bridges104A and double bridges 104B may be 0.045 mm. The increased width of theproximal single and double bridges 112 may further aid pushabilitybecause the additional width, and hence material, provides a larger loadpath for the longitudinal force from the pusher or delivery wire to betransmitted through the vessel-engaging member 100.

Distal Tips

In some embodiments, the vessel-engaging member 100 may also include ata distal end one or more open extending distal tips 116, 117, and 118.These distal tips 116-118 may extend from corresponding distal vertices107B of a distal row of struts. In FIG. 1A, for example, thevessel-engaging member 100 includes a first distal tip 116, a seconddistal tip 117, and a third distal tip 118, each directly extending froma distal vertex of the distal row. One of the distal tips may be longerthan the other or may extend out further. As shown in FIG. 1A, thesecond distal tip 117 is longer than the first and third distal tip, 116and 118 respectively. The first distal tip 116 is longer than the thirddistal tip 118.

In some embodiments, the distal tips may be configured to be non-linear.For example, referring to FIG. 2, the first distal tip 116 and thesecond distal tip 117 include an angle. When the vessel-engaging member100 is fully deployed, the angled protruding distal tips 116, 117, mayfold down toward the shorter protruding tip 118 to provide a narrowand/or tapered profile at the distal end of the vessel-engaging member100. Thus, when deployed, the vessel-engaging member 100 may be morenavigable than if the distal tips were not folded.

In some embodiments, the angled protruding distal tips 116, 117, mayensnare, capture, and/or grip portions of a thrombus. Because the angledprotruding distal tips 116, 117, may protrude inward slightly from therest of the vessel-engaging member 100, the thrombus may adhere to thedistal tips 116, 117. In some embodiments the distal tips 116-118 may bestaggered both circumferentially and longitudinally along the distal endof the vessel-engaging member 100. The staggered placement of distaltips 116-118 may allow the thrombus to adhere to multiple distal tips,for example at different locations along the length of the thrombus.

The distal tips may include, for example, a platinum distal marker band,as discussed further below. As a marker band, the distal element may beused during an imaging process to identify a location or locations ofthe vessel-engaging member 100 during a medical treatment procedure.

Radiopaque Markers

Turning back to FIG. 1A, radiopaque markers may be located adjacent theproximal or distal ends 101, 102 or both, and may be located at anyposition along the length of the vessel-engaging member 100 between theproximal and distal ends 101, 102. In some embodiments, the markers maybe located at or on the connection points 113 and/or distal tips116-118. The markers may be attached to the vessel-engaging member 100by techniques such as adhesives, heat fusion, interference fit,fasteners, intermediate members, coatings, or by other techniques.

In some embodiments, the markers are comprised of ultrasonic markers,MRI safe markers, or other markers. In some embodiments ultrasonicmarkers permit a physician to accurately determine the position of thevessel-engaging member 100 within a patient under ultrasonicvisualization. Ultrasonic visualization is especially useful forvisualizing the vessel-engaging member 100 during non-invasive follow-upand monitoring. Materials for an ultrasonic marker have an acousticaldensity sufficiently different from the medical to provide suitablevisualization via ultrasonic techniques. Exemplary materials comprisepolymers, metals such as tantalum, platinum, gold, tungsten and alloysof such metals, hollow glass spheres or microspheres, and othermaterials.

In some embodiments, MRI safe markers permit a physician to accuratelydetermine the position of the vessel-engaging member 100 within apatient under magnetic resonance imaging. MRI visualization isespecially useful for visualizing the vessel-engaging member 100 duringnon-invasive follow-up and monitoring. Exemplary materials for makingMRI safe marker have a magnetic signature sufficiently different fromthe medical device to provide suitable visualization via MRI techniques.Exemplary materials comprise polymers, metals such as tantalum,platinum, gold, tungsten and alloys of such metals, non-ferrousmaterials, and other materials.

Connection Mechanism

In some embodiments the connection mechanism 113 may include a generallynon-detachable interface or transition point between the vessel-engagingmember 100 and the delivery wire 153 (shown in FIG. 4). In someembodiments the connection mechanism 113 may be integrally formed withthe delivery wire 153 and/or vessel-engaging member 100. In someembodiments connection mechanisms 113 may include a releasableconnection mechanism for easily releasing the vessel-engaging member100.

Depending on the procedure and intended use of the vessel-engagingmember 100, it may be advantageous to have a connection mechanism 113that permits release of the vessel-engaging member 100. For example, thevessel-engaging member 100 may be used as an implantable member (e.g.,stent) that may be released through the connection mechanism 113 at astenosis, aneurysm, or other appropriate location in the anatomicallumen. The vessel-engaging member 100 may expand and engage a lumen wallso as to hold the lumen wall open and/or act as an occluding member.Specifically, the vessel-engaging member 100 may be used as ascaffolding to inhibit or prevent herniation or prolapse of objects(e.g., embolization coils, thrombi, etc.) out of a neck of an aneurysm.In another example, such as during a blood flow restoration procedure,it may prove difficult and/or dangerous to fully retrieve a thrombus dueto a complicated vasculature or the risk of damaging a lumen wall.Leaving the vessel-engaging member 100 behind may prove to be the onlyoption available to a surgeon or other medical personnel. In othercircumstances the vessel-engaging member 100 may include drug-eludingcapabilities, and/or may be coated with a particular type of drug thatfacilitates thrombus dissolution. It may be advantageous in suchcircumstances to release the vessel-engaging member 100 and allow thevessel-engaging member 100 to anchor the thrombus against the lumen wallwhile the thrombus is dissolved by the drug.

In some embodiments, the connection mechanism 113 may include anelectrolytically severable region. For example, referring to FIGS. 4-6,the connection mechanism 113 may comprise a connection that dissolvesunder the influence of electrical energy when in contact with anelectrolyte. The electrolytically severable region may include anexposed piece of electrolytically severable material, such as stainlesssteel, though other materials are also possible.

As depicted in FIGS. 4 and 5, the electrolytically severable region mayinclude a portion of the delivery wire 153. The delivery wire 153 mayinclude an electrolytically severable region comprising a loop structure152 that is configured to engage two tabs 154 extending from thevessel-engaging member 100. Each tab 154 includes an aperture 155 sizedto receive the loop structure 152 of the delivery wire 153. In someembodiments, the entire vessel-engaging member 100, the tab 154, or theaperture 155, may be coated be with an insulating coating, such asparylene (though other types of coating material are also possible), toelectrically insulate the vessel-engaging member 100 from the electricalenergy. In some embodiments, the vessel-engaging member 100 may beformed from a material that is not prone to electrolytic disintegration,such as NITINOL®. A portion of the delivery wire 153 may be isolated toprevent electrolytic disintegration of said portion. For example, aPolytetrafluoroethylene (PTFE) shrink tube 150 may be disposed over thedelivery wire 153 to prevent electrolytic disintegration of the deliverywire 153 at the shielded portion. Specifically, the shrink tube 150prevents the electrolyte (e.g., blood) from contacting the shieldedportion. In some embodiments, the loop structure 152 may be formed bybending the delivery wire 153 and securing the bent portion onto thedelivery wire 153 with a radiopaque marker 151. The radiopaque marker151 may be attached to the delivery wire 153 by techniques such asadhesives, heat fusion, interference fit, fasteners, intermediatemembers, coatings, or by other techniques.

Referring to FIG. 6, the delivery wire 153 may include a loop structure162 that is configured to engage an electrolytically severable region164 of the vessel-engaging member 100. The severable region 164 maycomprise a member extending between the first and second taperedsections, 114 and 115 respectively.

Overall, the structure of connection mechanism 113 may be configuredsuch that the vessel-engaging member 100 releases at a predeterminedpoint. For example, the vessel-engaging member 100 may generally beisolated from electric current, such that during detachment of thevessel-engaging member 100, only the electrolytically severable regiondisintegrates in blood, and the vessel-engaging member 100 separatesfrom the delivery wire 153 cleanly at the electrolytically severableregion, and is released into the anatomical lumen.

In some embodiments, the connection mechanism 113 may include amechanical connection. Referring to FIGS. 7-10, the connection mechanism113 may comprise two interlocking fingers 174 that are configured tocouple the delivery wire 153. Each interlocking finger 174 may comprisea tab 175 with fingers 176 extending therefrom, that are disposed on aproximal end of the vessel-engaging member 100. As depicted in FIG. 7,the fingers 176 may extend from opposite edges of the tab 175.Alternatively, as depicted in FIG. 8, the fingers 176 may extend from acommon edge of the tab 175. In either case, the tab 175 and fingers 176are configured to have a curvature for facilitating coupling with thedelivery wire 153.

Referring to FIGS. 9 and 10, the interlocking fingers 174 couple thedelivery wire 153 at a coupling area of the delivery wire 153 that isbetween a first and second bumper or radiopaque marker, 177A and 177Brespectively. The first and second radiopaque markers, 177A and 177Brespectively, prevent the interlocking fingers from sliding beyond thecoupling area and thereby act as stops for the interlocking fingers 174.The interlocking fingers 174 are forced onto the coupling area of thedelivery wire by an outer sheath or microcatheter 178 that surrounds theinterlocking fingers 174.

Referring to FIG. 10, proximal movement of the microcatheter 178 ordistal movement of the delivery wire 153, with the vessel-engagingmember 100 coupled thereto, releases the interlocking fingers 174 fromthe delivery wire 153 via expansion of the vessel-engaging member 100.Accordingly, upon expansion of the proximal end 101 of thevessel-engaging member 100, the interlocking fingers 174 release thedelivery wire 153, thereby releasing the vessel-engaging member 100 fromthe delivery wire 153.

Referring to FIGS. 11-13, the connection mechanism 113 may comprise aball 182, located at a distal end of the delivery wire 153, and twopaddles 184 configured to couple the ball 182. Each paddle 184 maycomprise an aperture 185 configured to couple to an outer surface of theball 182. Each paddle 184 may be configured with a channel 186 toprovide clearance for the delivery wire 153, so as to prevent aninterference between the paddle 184 and the delivery wire 153 when thepaddles 184 are coupled to the ball 182. Each paddle is disposed on aproximal end 101 of the vessel-engaging member 100.

As depicted in FIGS. 11-13, the paddles 184 couple the delivery wire 153at the ball 182. The paddles 184 may be forced onto the ball 182 by aretractable sleeve 187 that surrounds the paddles 184 and the ball 182.The sleeve 187 may be comprised of platinum, though other materials arealso possible. Proximal movement of the sleeve 187, via a wire 188 orother mechanical means, releases the paddles 184 from the delivery wire153 via expansion of the vessel-engaging member 100. Accordingly, uponexpansion of the proximal end 101 of the vessel-engaging member 100, thepaddles 184 release the ball 182 of the delivery wire 153, therebyreleasing the vessel-engaging member 100 from the delivery wire 153.

Referring to FIGS. 14-15, the connection mechanism 113 may comprise aplurality of grasping jaws 192 that are attached to a distal end of thedelivery wire 153. The grasping jaws 192 may, for example, comprise anAlligator Retrieving Device (“ARD”) as manufactured by Covidien®. Thegrasping jaws 192 may be configured to engage the proximal end 101 ofthe vessel-engaging member 100. As depicted in FIG. 15, the graspingjaws 192 may engage the open cells 127 adjacent the proximal end 101 ofthe vessel-engaging member 100. The grasping jaws 192 may be manipulatedto open and close by a retractable sleeve or microcatheter 178 thatsurrounds the grasping jaws 192. Proximal movement of the microcatheteror distal movement of the delivery wire 153 releases the grasping jaws192 from the vessel-engaging member 100.

The grasping jaws 192 may be configured to release the vessel-engagingmember 100 by allowing the tips of each grasping jaw to deflect andrelease the vessel-engaging member 100 upon proximal movement of thedelivery wire 153 and the grasping jaws 192. Once expanded within theanatomical lumen, friction between the outer surface of thevessel-engaging member 100 and the anatomical lumen, prevents thevessel-engaging member 100 from moving proximally with the delivery wire153 and the grasping jaws 192.

Referring to FIGS. 16-17, the connection mechanism 113 may comprise aninner sheath 194 that is configured to surround the vessel-engagingmember 100 and maintain the vessel-engaging member 100 in a compressedconfiguration. The inner sheath 194 has an outer diameter that is lessthan the inner diameter of the microcatheter 178. In some embodiments,the inner sheath 194 extends along the entire length of thevessel-engaging member 100. As depicted in FIG. 17, proximal movement ofthe inner sheath 194 or distal movement of the delivery wire 153, allowsthe vessel-engaging member 100 to expand in the anatomical lumen. Torelease the vessel-engaging member 100, the inner sheath 194 is movedproximal of the proximal end 101 of the vessel-engaging member 100,thereby allowing the vessel-engaging member to expand and be free fromthe inner sheath 194. To prevent the vessel-engaging member fromshifting during proximal retraction of the inner sheath 194, one or morebumpers 195 may be disposed along the delivery wire 153 to engage theproximal end 101 and/or the distal end 102 of the vessel-engaging member100 when the vessel-engaging member 100 is in the compressedconfiguration.

In some embodiments, one or more radiopaque markers may be disposedalong the delivery wire 153. For example, referring to FIGS. 16-17, aradiopaque marker 196 may be disposed at the distal end of the deliverywire 153. In other aspects, a radiopaque marker 197 may be disposedproximal of the vessel-engaging member 100.

The strut 103, single bridge 104A, and double bridge 104B configurationof the vessel-engaging member 100 may be formed, for example, by lasercutting a pre-formed tube or sheet, by interconnecting a multitude offilaments by laser welding, or by other suitable methods such aselectrochemical etching, grinding, piercing, electroforming, or othermeans. In one arrangement, the vessel-engaging member 100 may becomprised of metal, polymer, ceramic, permanent enduring materials, andmay comprise either of or both of non-bioabsorbable and bioabsorbablematerials. Exemplary materials include, but are not limited to,NITINOL®, stainless steel, cobalt chromium alloys, Elgiloy, magnesiumalloys, polylactic acid, poly glycolic acid, poly ester amide (PEA),poly ester urethane (PEU), amino acid based bioanalogous polymers,tungsten, tantalum, platinum, polymers, bio-polymers, ceramics,bio-ceramics, or metallic glasses. Part or all of the medical device mayelute over time substances such as drugs, biologics, gene therapies,antithrombotics, coagulants, anti-inflammatory drugs, immunomodulatordrugs, anti-proliferatives, migration inhibitors, extracellular matrixmodulators, healing promoters, re-endothelialization promoters, or othermaterials. In some embodiments, the vessel-engaging member 100 may beformed from materials having shape memory properties. In someembodiments, the vessel-engaging member 100 may be finished by processesto remove slag. In some embodiments, the vessel-engaging member 100 maybe subjected to a tempering treatment at temperatures customarilyapplied to the material so that the impressed structure is permanentlyestablished.

The vessel-engaging member 100 may have various lengths and diameters.For example, the vessel-engaging member 100 may have specificcross-sectional diameters, the diameters being measured when thevessel-engaging member 100 is fully free to expand, ranging from about 2mm to about 6 mm. If the vessel-engaging member 100 has a diameterbetween 3 mm and 4 mm, it may be used in a size 18 microcatheters (i.e.,microcatheters with an inner diameter of approximately 0.21 inch). Ifthe vessel-engaging member 100 has a diameter between 5 mm and 6 mm, itmay be used in a size 27 microcatheters (i.e., microcatheters with aninner diameter of approximately 0.027 inch). However, other suitablecross-sectional diameters may be used without deviating from the scopeof the subject technology. In some embodiments, the vessel-engagingmember may have lengths, measured proximally to distally along thelongitudinal axis 109, ranging from 15 mm to 40 mm, though other rangesand sizes are also possible.

Skilled artisans may implement the described functionality in varyingways for each particular application. Various components and blocks maybe arranged differently (for example, arranged in a different order, orpartitioned in a different way) all without departing from the scope ofthe subject technology. It is understood that the specific order orhierarchy of steps in the processes disclosed is an illustration ofexemplary approaches. Based upon design preferences, it is understoodthat the specific order or hierarchy of steps in the processes may berearranged. Some of the steps may be performed simultaneously. Theaccompanying method claims present elements of the various steps in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. The previousdescription provides various examples of the subject technology, and thesubject technology is not limited to these examples. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. Pronouns in themasculine (for example, his) include the feminine and neuter gender (forexample, her and its) and vice versa. Headings and subheadings, if any,are used for convenience only and do not limit the invention.

A phrase such as an “aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples. A phrase such as an aspectmay refer to one or more aspects and vice versa. A phrase such as an“aspect” does not imply that such aspect is essential to the subjecttechnology or that such aspect applies to all configurations of thesubject technology. A disclosure relating to an aspect may apply to allaspects, or one or more aspects. An aspect may provide one or moreexamples. A phrase such as an “aspect” may refer to one or more aspectsand vice versa. A phrase such as a “configuration” does not imply thatsuch configuration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A configuration may provide one or moreexamples. A phrase such as a “configuration” may refer to one or moreconfigurations and vice versa.

The word “exemplary” is used herein to mean “serving as an example orillustration.” Any aspect or design described herein as “exemplary” isnot necessarily to be construed as preferred or advantageous over otheraspects or designs.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. §112, sixth paragraph, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.” Furthermore, to the extent that the term “include,” “have,” or thelike is used in the description or the claims, such term is intended tobe inclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

What is claimed is:
 1. A medical device, comprising: a delivery wirehaving a proximal end and a distal end; and a vessel-engaging memberattached to the distal end of the delivery wire, the vessel-engagingmember comprising: a plurality of rows, each row having a plurality ofstruts arranged in an alternating pattern such that for each row, afirst set of vertices is positioned on a proximal side, and a second setof vertices is positioned on a distal side; a plurality of singlebridges positioned between adjacent rows, each of the bridges connectinga vertex of a first row with a corresponding vertex of an adjacentsecond row; and a plurality of double bridges positioned betweenadjacent rows, each of the double bridges connecting a vertex of a firstrow with two adjacent vertices of an adjacent second row, wherein eachof the plurality of double bridges is arranged generally along a lineprogressing laterally at an angle with respect to a longitudinal axis ofthe member.
 2. The medical device of claim 1, wherein the first set ofvertices are laterally offset from the second set of vertices.
 3. Themedical device of claim 1, wherein the plurality of single bridgespositioned between a first row and an adjacent second row extend fromthe second set of vertices of the first row, downward to the first setof vertices of the second row, and wherein the plurality of singlebridges positioned between the second row and an adjacent third rowextends from the second set of vertices of the second row, upward to thefirst set of vertices of the third row.
 4. The medical device of claim1, wherein the plurality of double bridges are more rigid than theplurality of single bridges and thereby communicate a larger proportionof a longitudinal force than the plurality of single bridges.
 5. Themedical device of claim 1, wherein the plurality of single bridgescomprises undulating members.
 6. The medical device of claim 1, whereinthe plurality of double bridges comprises undulating members.
 7. Themedical device of claim 1, wherein the single bridges positioned betweena first row and an adjacent second row alternate laterally with thedouble bridges positioned between said adjacent rows.
 8. The medicaldevice of claim 7, wherein the alternating single and double bridgesform a laterally-repeating pattern of two adjacent single bridges andone double bridge adjacent to one of the two adjacent single bridges. 9.The medical device of claim 8, wherein the single and double bridgespositioned between the second row and an adjacent third row form thesame laterally-repeating pattern as between the first row and the secondrow, wherein the double bridges between the second and third row areoffset laterally from the double bridges between the first and secondrow.
 10. The medical device of claim 8, wherein: the single and doublebridges positioned between the second row and an adjacent third row formthe same laterally-repeating pattern as between the first row and thesecond row; the single and double bridges positioned between the thirdrow and an adjacent fourth row form the same laterally-repeating patternas between the first row and the second row, and as between the secondrow and the third row; the double bridges between the second row and thethird row are aligned laterally with the double bridges between thefirst row and the second row; and the double bridges between the thirdrow and the fourth row are offset laterally from the double bridgesbetween the first row and the second row, and from the double bridgesbetween the second row and the third row.
 11. The medical device ofclaim 10, wherein the pattern thus formed by the double bridges betweenthe first row and the second row, the double bridges between the secondrow and the third row, and the double bridges between the third row andthe fourth row, consisting of two longitudinally adjacent, laterallyaligned sets of double bridges followed by one set of double bridgeslongitudinally adjacent to one of the two aligned sets and laterallyoffset therefrom, repeats along the length of the medical device. 12.The medical device of claim 10, wherein the double bridges between thethird row and the fourth row are offset laterally from the doublebridges between the first row and the second row, and from the doublebridges between the second row and the third row, to the next lateralinter-vertex position on the distal vertices of the third row.
 13. Themedical device of claim 1, wherein the plurality of single bridges andthe plurality of double bridges positioned between a first row and anadjacent second row are laterally offset from the plurality of singlebridges and the plurality of double bridges positioned between thesecond row and an adjacent third row.
 14. The medical device of claim 1,wherein an adjacent plurality of double bridges is positioned betweenthe second row and a third row, the adjacent plurality of double bridgesbeing longitudinally spaced from the plurality of double bridges. 15.The medical device of claim 1, further comprising first and secondtapered sections, each of the tapered sections projecting from aproximal row and tapering in a direction from the proximal row towardthe delivery wire.
 16. The medical device of claim 15, wherein the firsttapered section comprises a first and second connecting member withdistal ends connected to the proximal row and proximal ends connected tothe first tapered section.
 17. The medical device of claim 16, whereinthe first and second connecting members intersect.
 18. The medicaldevice of claim 15, wherein the first tapered section is connected tothe proximal row at a middle vertex and a first strut endpoint, and thesecond tapered section is connected to the proximal row at the middlevertex and a second strut endpoint.
 19. A medical device for insertioninto a vessel, comprising: a frame comprising a plurality of rows, eachrow having a plurality of struts arranged in an alternating pattern suchthat for each row, a first set of vertices is positioned on a proximalside, and a second set of vertices is positioned on a distal side offsetfrom the first set of vertices; a plurality of single bridges positionedbetween adjacent rows, each of the bridges connecting the second set ofvertices of a first row with the first set of vertices of a second row;and a plurality of double bridges positioned between adjacent rows, eachof the double bridges connecting a vertex of the first row with twovertices of the second row, wherein each of the plurality of doublebridges is arranged generally along a line progressing laterally at anangle with respect to a longitudinal axis of the member.
 20. The medicaldevice of claim 19, wherein the first set of vertices are laterallyoffset from the second set of vertices.
 21. The medical device of claim19, wherein the plurality of single bridges positioned between a firstrow and an adjacent second row extend from the second set of vertices ofthe first row, downward to the first set of vertices of the second row,and wherein the plurality of single bridges positioned between thesecond row and an adjacent third row extends from the second set ofvertices of the second row, upward to the first set of vertices of thethird row.
 22. The medical device of claim 19, wherein the plurality ofdouble bridges are more rigid than the plurality of single bridges andthereby communicate a larger proportion of a longitudinal force than theplurality of single bridges.
 23. The medical device of claim 19, whereinthe plurality of single bridges comprises undulating members.
 24. Themedical device of claim 19, wherein the plurality of double bridgescomprises undulating members.
 25. The medical device of claim 19,wherein the single bridges positioned between a first row and anadjacent second row alternate laterally with the double bridgespositioned between said adjacent rows.
 26. The medical device of claim25, wherein the alternating single and double bridges form alaterally-repeating pattern of two adjacent single bridges and onedouble bridge adjacent to one of the two adjacent single bridges. 27.The medical device of claim 26, wherein the single and double bridgespositioned between the second row and an adjacent third row form thesame laterally-repeating pattern as between the first row and the secondrow, wherein the double bridges between the second and third row areoffset laterally from the double bridges between the first and secondrow.
 28. The medical device of claim 26, wherein: the single and doublebridges positioned between the second row and an adjacent third row formthe same laterally-repeating pattern as between the first row and thesecond row; the single and double bridges positioned between the thirdrow and an adjacent fourth row form the same laterally-repeating patternas between the first row and the second row, and as between the secondrow and the third row; the double bridges between the second row and thethird row are aligned laterally with the double bridges between thefirst row and the second row; and the double bridges between the thirdrow and the fourth row are offset laterally from the double bridgesbetween the first row and the second row, and from the double bridgesbetween the second row and the third row.
 29. The medical device ofclaim 28, wherein the pattern thus formed by the double bridges betweenthe first row and the second row, the double bridges between the secondrow and the third row, and the double bridges between the third row andthe fourth row, consisting of two longitudinally adjacent, laterallyaligned sets of double bridges followed by one set of double bridgeslongitudinally adjacent to one of the two aligned sets and laterallyoffset therefrom, repeats along the length of the medical device. 30.The medical device of claim 28, wherein the double bridges between thethird row and the fourth row are offset laterally from the doublebridges between the first row and the second row, and from the doublebridges between the second row and the third row, to the next lateralinter-vertex position on the distal vertices of the third row.
 31. Themedical device of claim 19, wherein the plurality of single bridges andthe plurality of double bridges positioned between a first row and anadjacent second row are laterally offset from the plurality of singlebridges and the plurality of double bridges positioned between thesecond row and an adjacent third row.
 32. The medical device of claim19, wherein an adjacent plurality of double bridges is positionedbetween the second row and a third row, the adjacent plurality of doublebridges being longitudinally spaced from the plurality of doublebridges.
 33. The medical device of claim 19, further comprising firstand second tapered sections, each of the tapered sections projectingfrom a proximal row and tapering in a direction from the proximal rowtoward the delivery wire.
 34. The medical device of claim 33, whereinthe first tapered section comprises a first and second connecting memberwith distal ends connected to the proximal row and proximal endsconnected to the first tapered section.
 35. The medical device of claim34, wherein the first and second connecting members intersect.
 36. Themedical device of claim 33, wherein the first tapered section isconnected to the proximal row at a middle vertex and a first strutendpoint, and the second tapered section is connected to the proximalrow at the middle vertex and a second strut endpoint.